I've digitized all my sheet music and I display it on my iPad via forScore. I only have two complaints. The music is a little smaller on the iPad so I have to pay a little bit closer attention when reading it. I recently purchased a pair of reading glasses (I know) and that seems to be solving this problem. The second complaint is turning pages. The app has an easy enough gesture to reach up and flip the page but because it is not tactile like sheet music and because computers aren't perfect, sometimes it doesn't go just right and I end up turning two pages.

Today Macworld did a video review of the Air Turn device that solves this problem with a Bluetooth foot pedal. Tap it with your foot, and the page turns. This seems like a no-brainer for a professional musician. Maybe it's a Christmas list item for me.